From 92573f7be18bfca16dd3292cbe536d7d7912198f Mon Sep 17 00:00:00 2001 From: "Steinar H. Gunderson" Date: Sat, 8 Mar 2014 18:37:25 +0100 Subject: [PATCH 1/1] Make the initializing functions also drop fixed function usage. --- init.cpp | 122 ++++++++++++++++++++++++++++++------------------- texture1d.frag | 7 +++ 2 files changed, 83 insertions(+), 46 deletions(-) create mode 100644 texture1d.frag diff --git a/init.cpp b/init.cpp index 5717dda..4003163 100644 --- a/init.cpp +++ b/init.cpp @@ -5,6 +5,7 @@ #include #include "init.h" +#include "resource_pool.h" #include "util.h" using namespace std; @@ -27,6 +28,7 @@ namespace { void measure_texel_subpixel_precision() { + ResourcePool resource_pool; static const unsigned width = 4096; // Generate a destination texture to render to, and an FBO. @@ -64,8 +66,6 @@ void measure_texel_subpixel_precision() check_error(); glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE16F_ARB, 2, 0, GL_LUMINANCE, GL_FLOAT, texdata); check_error(); - glEnable(GL_TEXTURE_1D); - check_error(); // Basic state. glDisable(GL_BLEND); @@ -77,36 +77,51 @@ void measure_texel_subpixel_precision() glViewport(0, 0, width, 1); - glMatrixMode(GL_PROJECTION); - glLoadIdentity(); - glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0); - - glMatrixMode(GL_MODELVIEW); - glLoadIdentity(); + GLuint glsl_program_num = resource_pool.compile_glsl_program( + read_file("vs.vert"), read_file("texture1d.frag")); + glUseProgram(glsl_program_num); + check_error(); + glUniform1i(glGetUniformLocation(glsl_program_num, "tex"), 0); // Bind the 1D sampler. check_error(); // Draw the texture stretched over a long quad, interpolating it out. // Note that since the texel center is in (0.5), we need to adjust the // texture coordinates in order not to get long stretches of (1,1,1,...) // at the start and (...,0,0,0) at the end. - glBegin(GL_QUADS); - - glTexCoord1f(0.25f); - glVertex2f(0.0f, 0.0f); + float vertices[] = { + 0.0f, 0.0f, + 1.0f, 0.0f, + 1.0f, 1.0f, + 0.0f, 1.0f + }; + float texcoords[] = { + 0.25f, 0.0f, + 0.75f, 0.0f, + 0.75f, 0.0f, + 0.25f, 0.0f + }; - glTexCoord1f(0.75f); - glVertex2f(1.0f, 0.0f); - - glTexCoord1f(0.75f); - glVertex2f(1.0f, 1.0f); - - glTexCoord1f(0.25f); - glVertex2f(0.0f, 1.0f); + int position_attrib = glGetAttribLocation(glsl_program_num, "position"); + assert(position_attrib != -1); + int texcoord_attrib = glGetAttribLocation(glsl_program_num, "texcoord"); + assert(texcoord_attrib != -1); + glEnableVertexAttribArray(position_attrib); + check_error(); + glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, vertices); + check_error(); + glEnableVertexAttribArray(texcoord_attrib); + check_error(); + glVertexAttribPointer(texcoord_attrib, 2, GL_FLOAT, GL_FALSE, 0, texcoords); + check_error(); - glEnd(); + glDrawArrays(GL_QUADS, 0, 4); check_error(); - glDisable(GL_TEXTURE_1D); + glUseProgram(0); + check_error(); + glDisableVertexAttribArray(position_attrib); + check_error(); + glDisableVertexAttribArray(texcoord_attrib); check_error(); // Now read the data back and see what the card did. @@ -122,6 +137,7 @@ void measure_texel_subpixel_precision() biggest_jump = max(biggest_jump, out_data[i] - out_data[i - 1]); } + assert(biggest_jump > 0.0); movit_texel_subpixel_precision = biggest_jump; // Clean up. @@ -135,10 +151,14 @@ void measure_texel_subpixel_precision() check_error(); glDeleteTextures(1, &src_texnum); check_error(); + + resource_pool.release_glsl_program(glsl_program_num); } void measure_roundoff_problems() { + ResourcePool resource_pool; + // Generate a destination texture to render to, and an FBO. GLuint dst_texnum, fbo; @@ -180,8 +200,6 @@ void measure_roundoff_problems() check_error(); glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE32F_ARB, 512, 0, GL_LUMINANCE, GL_FLOAT, texdata); check_error(); - glEnable(GL_TEXTURE_1D); - check_error(); // Basic state. glDisable(GL_BLEND); @@ -193,34 +211,44 @@ void measure_roundoff_problems() glViewport(0, 0, 512, 1); - glMatrixMode(GL_PROJECTION); - glLoadIdentity(); - glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0); - - glMatrixMode(GL_MODELVIEW); - glLoadIdentity(); + GLuint glsl_program_num = resource_pool.compile_glsl_program( + read_file("vs.vert"), read_file("texture1d.frag")); + glUseProgram(glsl_program_num); check_error(); + glUniform1i(glGetUniformLocation(glsl_program_num, "tex"), 0); // Bind the 1D sampler. // Draw the texture stretched over a long quad, interpolating it out. - glBegin(GL_QUADS); - - glTexCoord1f(0.0f); - glVertex2f(0.0f, 0.0f); - - glTexCoord1f(1.0f); - glVertex2f(1.0f, 0.0f); - - glTexCoord1f(1.0f); - glVertex2f(1.0f, 1.0f); - - glTexCoord1f(0.0f); - glVertex2f(0.0f, 1.0f); - - glEnd(); + float vertices[] = { + 0.0f, 0.0f, + 1.0f, 0.0f, + 1.0f, 1.0f, + 0.0f, 1.0f + }; + float texcoords[] = { + 0.25f, 0.0f, + 0.75f, 0.0f, + 0.75f, 0.0f, + 0.25f, 0.0f + }; + int position_attrib = glGetAttribLocation(glsl_program_num, "position"); + assert(position_attrib != -1); + int texcoord_attrib = glGetAttribLocation(glsl_program_num, "texcoord"); + assert(texcoord_attrib != -1); + glEnableVertexAttribArray(position_attrib); + check_error(); + glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, vertices); + check_error(); + glEnableVertexAttribArray(texcoord_attrib); check_error(); + glVertexAttribPointer(texcoord_attrib, 2, GL_FLOAT, GL_FALSE, 0, texcoords); + check_error(); + glDrawArrays(GL_QUADS, 0, 4); - glDisable(GL_TEXTURE_1D); + glUseProgram(0); + check_error(); + glDisableVertexAttribArray(position_attrib); check_error(); + glDisableVertexAttribArray(texcoord_attrib); // Now read the data back and see what the card did. (Ignore the last value.) // (We only look at the red channel; the others will surely be the same.) @@ -251,6 +279,8 @@ void measure_roundoff_problems() check_error(); glDeleteTextures(1, &src_texnum); check_error(); + + resource_pool.release_glsl_program(glsl_program_num); } bool check_extensions() diff --git a/texture1d.frag b/texture1d.frag new file mode 100644 index 0000000..4f8b981 --- /dev/null +++ b/texture1d.frag @@ -0,0 +1,7 @@ +uniform sampler1D tex; +varying vec2 tc; + +void main() +{ + gl_FragColor = texture1D(tex, tc.x); +} -- 2.39.2