OpenGL 3.1 core profile support.
[ipdf/code.git] / src / screen.cpp
index 2764ef7..40754b3 100644 (file)
@@ -1,11 +1,63 @@
 #include "common.h"
 #include "screen.h"
 
-#include "SDL_opengl.h"
+#include "gl_core44.h"
+#include <fcntl.h> // for access(2)
+#include <unistd.h> // for access(2)
+
+#include "shaderprogram.h"
+
+#define BASICTEX_VERT \
+       "#version 140\n"\
+       "#extension GL_ARB_shading_language_420pack : require\n"\
+       "#extension GL_ARB_explicit_attrib_location : require\n"\
+       "\n"\
+       "layout(std140, binding=0) uniform Viewport\n"\
+       "{\n"\
+       "\tfloat width;\n"\
+       "\tfloat height;\n"\
+       "};\n"\
+       "\n"\
+       "layout(location = 0) in vec2 position;\n"\
+       "layout(location = 1) in vec2 tex_coord;\n"\
+       "\n"\
+       "out vec2 fp_tex_coord;\n"\
+       "\n"\
+       "void main()\n"\
+       "{\n"\
+       "\t// Transform to clip coordinates (-1,1, -1,1).\n"\
+       "\tgl_Position.x = (position.x*2/width) - 1;\n"\
+       "\tgl_Position.y = 1 - (position.y*2/height);\n"\
+       "\tgl_Position.z = 0.0;\n"\
+       "\tgl_Position.w = 1.0;\n"\
+       "\tfp_tex_coord = tex_coord;\n"\
+       "}\n"
+
+#define BASICTEX_FRAG \
+       "#version 140\n"\
+       "\n"\
+       "in vec2 fp_tex_coord;\n"\
+       "\n"\
+       "out vec4 output_colour;\n"\
+       "\n"\
+       "uniform sampler2D tex;\n"\
+       "uniform vec4 colour;\n"\
+       "\n"\
+       "void main()\n"\
+       "{\n"\
+       "\toutput_colour = colour;\n"\
+       "\toutput_colour.a = texture(tex, fp_tex_coord).r;\n"\
+       "}\n"
 
 using namespace IPDF;
 using namespace std;
 
+static void opengl_debug_callback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* msg, const void *data)
+{
+       Error("OpenGL Error (%d): %s", id, msg);
+}
+
+
 Screen::Screen()
 {
        SDL_Init(SDL_INIT_VIDEO);
@@ -17,8 +69,54 @@ Screen::Screen()
                Fatal("Couldn't create window!");
        }
 
+       SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+       SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 1);
+       SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
+       SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+
        m_gl_context = SDL_GL_CreateContext(m_window);
 
+       ogl_LoadFunctions();
+
+       // Why is this so horribly broken?
+       if (ogl_IsVersionGEQ(3,0))
+       {
+               Fatal("We require OpenGL 3.1, but you have version %d.%d!",ogl_GetMajorVersion(), ogl_GetMinorVersion());
+       }
+
+       if (!SDL_GL_ExtensionSupported("GL_ARB_shading_language_420pack"))
+       {
+               Fatal("Your system does not support the ARB_shading_language_420pack extension, which is required.");
+       }
+
+       if (!SDL_GL_ExtensionSupported("GL_ARB_explicit_attrib_location"))
+       {
+               Fatal("Your system does not support the ARB_explicit_attrib_location extension, which is required.");
+       }
+
+       glDebugMessageCallback(opengl_debug_callback, 0);
+
+       GLuint default_vao;
+       glGenVertexArrays(1, &default_vao);
+       glBindVertexArray(default_vao);
+
+       //TODO: Error checking.
+       m_texture_prog.AttachVertexProgram(BASICTEX_VERT);
+       m_texture_prog.AttachFragmentProgram(BASICTEX_FRAG);
+       m_texture_prog.Link();
+       m_texture_prog.Use();
+
+       // We always want to use the texture bound to texture unit 0.
+       GLint texture_uniform_location = m_texture_prog.GetUniformLocation("tex");
+       glUniform1i(texture_uniform_location, 0);
+
+       m_colour_uniform_location = m_texture_prog.GetUniformLocation("colour");
+
+       m_viewport_ubo.SetUsage(GraphicsBuffer::BufferUsageDynamicDraw);
+       m_viewport_ubo.SetType(GraphicsBuffer::BufferTypeUniform);
+
+       m_debug_font_atlas = 0;
+
        ResizeViewport(800, 600);
 
        Clear();
@@ -46,6 +144,8 @@ void Screen::ResizeViewport(int width, int height)
        glViewport(0, 0, width, height);
        m_viewport_width = width;
        m_viewport_height = height;
+       GLfloat viewportfloats[] = {(float)width, (float)height};
+       m_viewport_ubo.Upload(sizeof(float)*2, viewportfloats);
 }
 
 bool Screen::PumpEvents()
@@ -128,6 +228,8 @@ void Screen::SetMouseCursor(Screen::MouseCursors cursor)
 
 void Screen::Present()
 {
+       if (m_debug_font_atlas)
+               DebugFontFlush();
        SDL_GL_SwapWindow(m_window);
 }
 
@@ -140,8 +242,7 @@ void Screen::ScreenShot(const char * filename) const
        unsigned char * pixels = new unsigned char[w*h*4];
        if (pixels == NULL)
                Fatal("Failed to allocate %d x %d x 4 = %d pixel array", w, h, w*h*4);
-       glReadBuffer(GL_FRONT);
-       glPixelStorei(GL_PACK_ALIGNMENT, 1);
+
        for (int y = 0; y < h; ++y)
        {
                glReadPixels(0,h-y-1,w, 1, GL_RGBA, GL_UNSIGNED_BYTE, &pixels[y*w*4]);
@@ -172,6 +273,11 @@ void Screen::ScreenShot(const char * filename) const
  */
 void Screen::RenderBMP(const char * filename) const
 {
+       if (access(filename, R_OK) == -1)
+       {
+               Error("No such file \"%s\" - Nothing to render - You might have done this deliberately?", filename);
+               return;
+       }
        SDL_Surface * bmp = SDL_LoadBMP(filename);
        if (bmp == NULL)
                Fatal("Failed to load BMP from %s - %s", filename, SDL_GetError());
@@ -195,9 +301,23 @@ void Screen::RenderBMP(const char * filename) const
 
        //Debug("SDL_Surface %d BytesPerPixel, format %d (RGB = %d, BGR = %d, RGBA = %d, BGRA = %d)", bmp->format->BytesPerPixel, texture_format, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA);
 
+       m_texture_prog.Use();
+       GraphicsBuffer quad_vertex_buffer;
+       quad_vertex_buffer.SetUsage(GraphicsBuffer::BufferUsageStaticDraw);
+       quad_vertex_buffer.SetType(GraphicsBuffer::BufferTypeVertex);
+       GLfloat quad[] = { 
+               0, 0, 0, 0,
+               1, 0, ViewportWidth(), 0,
+               1, 1, ViewportWidth(), ViewportHeight(),
+               0, 1, 0, ViewportHeight()
+       };
+       quad_vertex_buffer.Upload(sizeof(GLfloat) * 16, quad);
+       quad_vertex_buffer.Bind();
+       m_viewport_ubo.Bind();
+
+       glUniform4f(m_colour_uniform_location, 1.0f, 1.0f, 1.0f, 1.0f);
 
        GLuint texID;
-       glEnable(GL_TEXTURE_2D);
        glGenTextures(1, &texID);
        glBindTexture(GL_TEXTURE_2D, texID);
 
@@ -208,20 +328,14 @@ void Screen::RenderBMP(const char * filename) const
 
        glTexImage2D(GL_TEXTURE_2D, 0, bmp->format->BytesPerPixel, w, h, 0, texture_format, GL_UNSIGNED_BYTE, bmp->pixels);
 
-       glMatrixMode(GL_PROJECTION);
-       glLoadIdentity();
-       glOrtho(0.0, 1.0, 1.0, 0.0, -1.f, 1.f);
-       glMatrixMode(GL_MODELVIEW);
-       glLoadIdentity();
+       glEnableVertexAttribArray(0);
+       glEnableVertexAttribArray(1);
+       glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4*sizeof(float), (void*)(2*sizeof(float)));
+       glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4*sizeof(float), 0);
+       glDisableVertexAttribArray(1);
+       glDisableVertexAttribArray(0);
+       glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
-       glBegin(GL_QUADS);
-               glTexCoord2i(0,0); glVertex2f(0,0);
-               glTexCoord2i(1,0); glVertex2f(1,0);
-               glTexCoord2i(1,1); glVertex2f(1,1);
-               glTexCoord2i(0,1); glVertex2f(0,1);
-       glEnd();
-
-       glDisable(GL_TEXTURE_2D);
        SDL_FreeSurface(bmp);   
 }
 
@@ -239,42 +353,103 @@ void Screen::DebugFontInit(const char *name, float font_size)
        free(font_file_data);
        glGenTextures(1, &m_debug_font_atlas);
        glBindTexture(GL_TEXTURE_2D, m_debug_font_atlas);
-       glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, 1024,1024, 0, GL_ALPHA, GL_UNSIGNED_BYTE, font_atlas_data);
+       glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, 1024,1024, 0, GL_RED, GL_UNSIGNED_BYTE, font_atlas_data);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        m_debug_font_size = font_size;
+
+       m_debug_font_vertices.SetUsage(GraphicsBuffer::BufferUsageStreamDraw);
+       m_debug_font_vertices.SetType(GraphicsBuffer::BufferTypeVertex);
+       m_debug_font_vertices.Upload(8192, nullptr);
+       m_debug_font_vertex_head = 0;
+
+       m_debug_font_indices.SetUsage(GraphicsBuffer::BufferUsageStreamDraw);
+       m_debug_font_indices.SetType(GraphicsBuffer::BufferTypeIndex);
+       m_debug_font_indices.Resize(500);
+       m_debug_font_index_head = 0;
 }
 
 void Screen::DebugFontClear()
 {
        m_debug_font_x = m_debug_font_y = 0;
+       if (!m_debug_font_atlas) return;
        DebugFontPrint("\n");
 }
 
-void Screen::DebugFontPrint(const char* str)
+void Screen::DebugFontFlush()
 {
-       glMatrixMode(GL_PROJECTION);
-       glPushMatrix();
-       glLoadIdentity();
-       glOrtho(0,ViewportWidth(), ViewportHeight(), 0, -1, 1);
-       glMatrixMode(GL_MODELVIEW);
-       glPushMatrix();
-       glLoadIdentity();
-       
-       
        
-       glEnable(GL_TEXTURE_2D);
+               
        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
        glBindTexture(GL_TEXTURE_2D, m_debug_font_atlas);
-       glBegin(GL_QUADS);
+
+       m_texture_prog.Use();
+       m_viewport_ubo.Bind();
+       m_debug_font_vertices.Bind();
+       m_debug_font_indices.Bind();
+       glUniform4f(m_colour_uniform_location, 0,0,0,1);
+       glEnableVertexAttribArray(0);
+       glEnableVertexAttribArray(1);
+       glEnable(GL_PRIMITIVE_RESTART);
+       glPrimitiveRestartIndex(65535);
+       glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4*sizeof(float), (void*)(2*sizeof(float)));
+       glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4*sizeof(float), 0);
+       glDrawElements(GL_TRIANGLE_STRIP, m_debug_font_index_head, GL_UNSIGNED_SHORT, 0);
+       glDisable(GL_PRIMITIVE_RESTART);
+       glDisableVertexAttribArray(1);
+       glDisableVertexAttribArray(0);
+
+       glDisable(GL_BLEND);
+
+       m_debug_font_vertex_head = 0;
+       m_debug_font_index_head = 0;
+}
+
+void Screen::DebugFontPrint(const char* str)
+{
+       if (!m_debug_font_atlas) return;
+
+       float *vertexData = (float*)m_debug_font_vertices.MapRange(m_debug_font_vertex_head*sizeof(float), m_debug_font_vertices.GetSize() - m_debug_font_vertex_head*sizeof(float), false, true, true);
+       uint16_t *indexData = (uint16_t*)m_debug_font_indices.MapRange(m_debug_font_index_head*sizeof(uint16_t), m_debug_font_indices.GetSize() - m_debug_font_index_head*sizeof(uint16_t), false, true, true);
        while (*str) {
+               if ((m_debug_font_vertex_head*sizeof(float) + 16*sizeof(float) >= m_debug_font_vertices.GetSize() ) ||
+                       (m_debug_font_index_head*sizeof(uint16_t) + 5*sizeof(uint16_t) >= m_debug_font_indices.GetSize()))
+               {
+                       m_debug_font_indices.UnMap();
+                       m_debug_font_vertices.UnMap();
+                       DebugFontFlush();
+                       DebugFontPrint(str);
+                       return;
+               }
                if (*str >= 32 && *str < 128) {
                        stbtt_aligned_quad q;
                        stbtt_GetBakedQuad(m_debug_font_rects, 1024,1024, *str-32, &m_debug_font_x,&m_debug_font_y,&q,1);
-                       glTexCoord2f(q.s0,q.t0); glVertex2f(q.x0,q.y0);
-                       glTexCoord2f(q.s1,q.t0); glVertex2f(q.x1,q.y0);
-                       glTexCoord2f(q.s1,q.t1); glVertex2f(q.x1,q.y1);
-                       glTexCoord2f(q.s0,q.t1); glVertex2f(q.x0,q.y1);
+                       *vertexData = q.s0; vertexData++;
+                       *vertexData = q.t0; vertexData++;
+                       *vertexData = q.x0; vertexData++;
+                       *vertexData = q.y0; vertexData++;
+                       *vertexData = q.s1; vertexData++;
+                       *vertexData = q.t0; vertexData++;
+                       *vertexData = q.x1; vertexData++;
+                       *vertexData = q.y0; vertexData++;
+                       *vertexData = q.s1; vertexData++;
+                       *vertexData = q.t1; vertexData++;
+                       *vertexData = q.x1; vertexData++;
+                       *vertexData = q.y1; vertexData++;
+                       *vertexData = q.s0; vertexData++;
+                       *vertexData = q.t1; vertexData++;
+                       *vertexData = q.x0; vertexData++;
+                       *vertexData = q.y1; vertexData++;
+
+                       *indexData = m_debug_font_vertex_head/4; indexData++;
+                       *indexData = m_debug_font_vertex_head/4+1; indexData++;
+                       *indexData = m_debug_font_vertex_head/4+3; indexData++;
+                       *indexData = m_debug_font_vertex_head/4+2; indexData++;
+                       *indexData = 65535; indexData++;
+
+                       m_debug_font_vertex_head += 16;
+                       m_debug_font_index_head += 5;
+
                }
                else if (*str == '\n')
                {
@@ -283,12 +458,9 @@ void Screen::DebugFontPrint(const char* str)
                }
                ++str;
        }
-       glEnd();
-       glDisable(GL_BLEND);
-       glDisable(GL_TEXTURE_2D);
-       glPopMatrix();
-       glMatrixMode(GL_MODELVIEW);
-       glPopMatrix();
+       m_debug_font_indices.UnMap();
+       m_debug_font_vertices.UnMap();
+       //DebugFontFlush();
 }
 
 void Screen::DebugFontPrintF(const char *fmt, ...)

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