CubicSDR/src/visual/WaterfallContext.cpp

#include "WaterfallContext.h"
#include "WaterfallCanvas.h"
#include "CubicSDR.h"

WaterfallContext::WaterfallContext(WaterfallCanvas *canvas, wxGLContext *sharedContext) :
        PrimaryGLContext(canvas, sharedContext), waterfall_lines(0), waterfall_slice(NULL), fft_size(0), activeTheme(NULL) {
    for (int i = 0; i < 2; i++) {
        waterfall[i] = 0;
    }
}

void WaterfallContext::Setup(int fft_size_in, int num_waterfall_lines_in) {
    waterfall_lines = num_waterfall_lines_in;
    fft_size = fft_size_in;

    int half_fft_size = fft_size / 2;

    for (int i = 0; i < 2; i++) {
        if (waterfall[i]) {
            glDeleteTextures(1, &waterfall[i]);
            waterfall[i] = 0;
        }

        waterfall_ofs[i] = waterfall_lines - 1;
    }
    // Stagger memory updates at half intervals for tiles
}

void WaterfallContext::refreshTheme() {
    glEnable (GL_TEXTURE_2D);

    for (int i = 0; i < 2; i++) {
        glBindTexture(GL_TEXTURE_2D, waterfall[i]);

        glPixelTransferi(GL_MAP_COLOR, GL_TRUE);
        glPixelMapfv(GL_PIXEL_MAP_I_TO_R, 256, &(ThemeMgr::mgr.currentTheme->waterfallGradient.getRed())[0]);
        glPixelMapfv(GL_PIXEL_MAP_I_TO_G, 256, &(ThemeMgr::mgr.currentTheme->waterfallGradient.getGreen())[0]);
        glPixelMapfv(GL_PIXEL_MAP_I_TO_B, 256, &(ThemeMgr::mgr.currentTheme->waterfallGradient.getBlue())[0]);
    }
}

void WaterfallContext::Draw(std::vector<float> &points) {

    int half_fft_size = fft_size / 2;

    glEnable (GL_TEXTURE_2D);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);

    if (!waterfall[0]) {
        glGenTextures(2, waterfall);

        unsigned char *waterfall_tex;

        waterfall_tex = new unsigned char[half_fft_size * waterfall_lines];
        memset(waterfall_tex, 0, half_fft_size * waterfall_lines);

        for (int i = 0; i < 2; i++) {
            glBindTexture(GL_TEXTURE_2D, waterfall[i]);
            glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

            glBindTexture(GL_TEXTURE_2D, waterfall[i]);
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, half_fft_size, waterfall_lines, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, (GLvoid *) waterfall_tex);
        }

		if (waterfall_slice != NULL) {
			delete waterfall_slice;
		}
		waterfall_slice = new unsigned char[half_fft_size];

        delete waterfall_tex;
    }

    if (activeTheme != ThemeMgr::mgr.currentTheme) {
        refreshTheme();
        activeTheme = ThemeMgr::mgr.currentTheme;
    }

    if (points.size()) {
        for (int j = 0; j < 2; j++) {
            for (int i = 0, iMax = half_fft_size; i < iMax; i++) {
                float v = points[(j * half_fft_size + i) * 2 + 1];

                float wv = v < 0 ? 0 : (v > 0.99 ? 0.99 : v);

                waterfall_slice[i] = (unsigned char) floor(wv * 255.0);
            }

            glBindTexture(GL_TEXTURE_2D, waterfall[j]);
            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, waterfall_ofs[j], half_fft_size, 1, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, (GLvoid *) waterfall_slice);

            if (waterfall_ofs[j] == 0) {
                waterfall_ofs[j] = waterfall_lines;
            }

            waterfall_ofs[j]--;
        }
    }

    glColor3f(1.0, 1.0, 1.0);

    GLint vp[4];
    glGetIntegerv(GL_VIEWPORT, vp);

    float viewWidth = (float) vp[2];
    float viewHeight = (float) vp[3];

    // some bias to prevent seams at odd scales
    float half_pixel = 1.0 / viewWidth;
    float half_texel = 1.0 / (float) half_fft_size;
    float vtexel = 1.0 / (float) waterfall_lines;
    float vofs = (float) (waterfall_ofs[0] + 1) * vtexel;

    glBindTexture(GL_TEXTURE_2D, waterfall[0]);
    glBegin (GL_QUADS);
    glTexCoord2f(0.0 + half_texel, 1.0 + vofs);
    glVertex3f(-1.0, -1.0, 0.0);
    glTexCoord2f(1.0 - half_texel, 1.0 + vofs);
    glVertex3f(0.0 + half_pixel, -1.0, 0.0);
    glTexCoord2f(1.0 - half_texel, 0.0 + vofs);
    glVertex3f(0.0 + half_pixel, 1.0, 0.0);
    glTexCoord2f(0.0 + half_texel, 0.0 + vofs);
    glVertex3f(-1.0, 1.0, 0.0);
    glEnd();

    vofs = (float) (waterfall_ofs[1] + 1) * vtexel;
    glBindTexture(GL_TEXTURE_2D, waterfall[1]);
    glBegin(GL_QUADS);
    glTexCoord2f(0.0 + half_texel, 1.0 + vofs);
    glVertex3f(0.0 - half_pixel, -1.0, 0.0);
    glTexCoord2f(1.0 - half_texel, 1.0 + vofs);
    glVertex3f(1.0, -1.0, 0.0);
    glTexCoord2f(1.0 - half_texel, 0.0 + vofs);
    glVertex3f(1.0, 1.0, 0.0);
    glTexCoord2f(0.0 + half_texel, 0.0 + vofs);
    glVertex3f(0.0 - half_pixel, 1.0, 0.0);
    glEnd();

    glBindTexture(GL_TEXTURE_2D, 0);

    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glDisable(GL_TEXTURE_2D);
}